Perpustakaan Digital ITB

Carbon dioxide-enhanced gas recovery (CO2-EGR) offers a dual solution to increase natural gas production while storing CO2 in depleted gas reservoirs. However, CO2-EGR implementation faces significant technical challenges related to the reservoir temperature changes and CO2 breakthrough effects, which remain understudied in terms of their sensitivity to injection operating parameters. This study investigates the effects of injection pressure, injection temperature, and reservoir permeability on reservoir temperature changes and CO2 breakthrough through a conceptual reservoir simulation built in tNavigator, representing a depleted gas reservoir with an initial pressure of 1,450 psi and a temperature of 212°F. Ten scenarios are simulated, varying the injection pressure from 1,500 to 6,000 psi, the injection temperature from 90 to 180°F, and the reservoir permeability from 50 to 200 mD. Simulation results show that higher injection pressure and reservoir permeability significantly increase CH4 production and broaden the distribution of CO2 within the reservoir, while injection temperature has no significant effect on fluid flow, consistent with Darcy's law. CO2 breakthrough occurs at injection pressures of 4,500 psi at 7 years after injection and 6,000 psi at 5 years after injection, as well as at permeability of 100 mD at 9 years after injection and 200 mD at 4 years after injection, while no breakthrough is observed in all injection temperature scenarios. Based on these findings, the optimal CO2-EGR performance in this reservoir model are injection pressures of 3,000 psi and permeability of 75 mD, which minimizes the risk of breakthrough. The finding in this thesis provide insights into optimal operating conditions to maximize gas recovery